Gastrointestinal basidiobolomycosis: an emerging fungal infection causing bowel perforation in a child

Abstract

Basidiobolomycosis is an unusual fungal skin infection that rarely involves the gastrointestinal (GI) tract. We report a 10-year-old boy diagnosed as suffering GI basidiobolomycosis after being misdiagnosed first as suffering intestinal malignancy then schistosomiasis. The patient presented with fever, abdominal pain, vomiting, abdominal tenderness and rigidity with marked blood eosinophilia. Abdominal ultrasonographic and computed tomographic scans revealed a large caecal mass. Biopsy of the mass showed transmural granulomatous inflammation interpreted as schistosomal granuloma, ruling out lymphoma. The patient's condition deteriorated despite anti-schistosomal therapy. Emergency surgery was then performed, and caecal perforation was found. The mass was excised; cultures were negative and histopathological examination was suggestive of schistosomal granuloma. The mass recurred 3 weeks post-operatively. Secondopinion histopathological examination diagnosed Basidiobolus ranarum infection. Treatment with itraconazole produced marked improvement, with diminution of the mass. B. ranarum was unequivocally identified in the archival formalin-fixed and paraffin-embedded (FFPE) tissue by PCR. This case emphasizes the need to consider GI basidiobolomycosis in children presenting with fever, abdominal mass and eosinophilia, especially those complicated by bowel perforation. IntroductionBasidiobolus species are filamentous fungi that belong to the order Entomophthorales. Unlike other fungi (e.g. Mucorales) classified to the former zygomycetes, they cause subcutaneous zygomycosis in healthy individuals (Singh et al., 2008). Basidiobolus ranarum was first described as an isolate from frogs in 1886. It was cultured from frogs' intestinal contents and excreta (Ribes et al., 2000). It is commonly found in soil and decaying vegetable matter. It is occasionally present as a commensal in the gastrointestinal (GI) tracts of amphibians, reptiles, fish and mammals such as frogs, toads, turtles, fish, chameleons, horses, dogs and bats (Kaufman et al., 1990;Zahari et al., 1990;Gugnani, 1999). The micro-organism was first isolated in 1955 from decaying plants in the United States. Subsequently it was found in soil and vegetation worldwide (Greer & Friedman, 1966). Basidiobolus is endemic in Uganda and certain other areas of Africa, and in parts of Asia including India (Ribes et al., 2000). In the past, clinical isolates of Basidiobolus were classified as B. ranarum, B. meristosporus and B. haptosporus. However, recent taxonomic studies based on antigenic analysis, isoenzyme banding and restriction enzyme analysis indicate that all human pathogens belong to B. ranarum. In two studies, B. ranarum was commonly isolated from South India (Khan et al., 2001;Sujatha et al., 2003).Zygomycosis is characterized by tissue invasion with broad, non-septate hyphae of fungal species such as Rhizopus, Rhizomucor, Absidia and Basidiobolus. Fungal elements of B. ranarum include hyphae and zygospores (Hocquet, 1979;Gugnani, 1999). The hyphae are thin-wall...

Surgical management of gastrointestinal basidiobolomycosis in pediatric patients

“…It presents vaguely with nonspecific abdominal pain and fever, often leading to a delayed diagnosis, as in many of our patients [10]. Complications include bowel perforation [11], obstructive uropathy [6], esophageal varices, duodenobiliary fistula [7], and death [7,12,13]. In our series, 2 patients had unresectable, disseminated disease, and both died shortly after diagnosis.…”

Gastrointestinal basidiobolomycosis with hepatic dissemination: a case report

“…The presence of an abdominal mass may be confused with malignancy, appendicular mass, Crohn’s disease, intestinal tuberculosis, sarcoidosis and amoebiasis (Ribes et al ., 2000). However, the characteristic histopathological features are the key in the diagnosis of all cases, together with fungal culture in some cases (Al-Qahtani et al ., 2013; El–Shabrawi et al ., 2011). This means that in cases where there is a lack of awareness and the facilities to diagnose such a rare disease, the diagnosis will be missed and such patients are at increased risk of morbidity.…”

Contribution of Ultra Deep Sequencing in the Clinical Diagnosis of a New Fungal Pathogen Species: Basidiobolus meristosporus

“…Alternatively, molecular methods such as DNA barcoding, on isolated colonies, offer a practical approach for species identification (Irinyi et al, 2015). In culture negative cases, sequencing of a PCR product from tissue could be performed as an alternative means of diagnosis (El-Shabrawi et al, 2011). However, the presence of several coexisting species may hamper sequence reading.…”